The light at the end of the tunnel. An out-of-body experience. Your life flashing before your eyes. According to Scientific American's Charles Q. Choi, 3% of Americans have had a near-death experience; now scientists are beginning to unravel the biological roots of these experiences.

Choi writes:

Near-death experiences are often thought of as mystical phenomena, but research is now revealing scientific explanations for virtually all of their common features.

...Recently, a host of studies has revealed potential underpinnings for all the elements of such experiences. "Many of the phenomena associated with near-death experiences can be biologically explained," says neuroscientist Dean Mobbs, at the University of Cambridge's Medical Research Council Cognition and Brain Sciences Unit.

You can read more about the biology underpinning everything from out-of-body experiences to walking corpse syndrome over at Scientific American.